Vessels, Net (Details)	12 Months Ended
	Mar. 31, 2018 USD ($) item	Mar. 31, 2017 USD ($) item	Mar. 31, 2016 USD ($)
Accumulated depreciation
Vessels, net	$ 1,539,111,833	$ 1,603,469,247
Vessels
Cost
Balance at the beginning of the period	1,728,769,295	1,727,979,929
Other additions	218,685	984,639
Transfers out		(195,273)
Balance at the end of the period	1,728,987,980	1,728,769,295
Accumulated depreciation
Balance at the beginning of the period	(125,300,048)	(60,755,453)
Impairment	0	0
Depreciation	(64,576,099)	(64,544,595)
Balance at the end of the period	(189,876,147)	(125,300,048)
Vessels, net	$ 1,539,111,833	$ 1,603,469,247	$ 1,667,224,476
Number of vessels with capital improvements | item	1	2
Mortgaged VLGC vessels, carrying value	$ 1,539,100,000	$ 1,603,500,000